In the 5-year follow-up of the Korean KLASS-02 trial reported in JAMA Surgery, Son et al found similar 5-year overall survival and relapse-free survival among patients with R0 resection using laparoscopic vs open distal gastrectomy in patients with locally advanced gastric cancer. Late complications were reduced with laparoscopic gastrectomy.
The primary analysis of the trial showed that laparoscopic gastrectomy was noninferior to open surgery in 3-year relapse-free survival.
Study Details
In the multicenter trial, 1,050 patients were randomly assigned between November 2011 and April 2015 to receive laparoscopic or open gastrectomy. A total of 974 patients (full analysis set) were treated with R0 resection, comprising 492 in the laparoscopic group and 482 in the open gastrectomy group.
Key Findings
The last enrolled patient was monitored for ≥ 5 years. Median follow-up was 69.4 months (interquartile range = 3.3–112.9 months).
The 5-year overall survival rate was 88.9% (95% confidence interval [CI] = 86.0%–91.8%) in the laparoscopic group vs 88.7% (95% CI = 85.8%-91.6%) in the open surgery group. Relapse-free survival at 5 years was 79.5% (95% CI = 75.9%-83.2%) vs 81.1% (95% CI = 77.7%–84.8%), with no significant difference between groups observed for either outcome. No significant differences in overall survival with laparoscopy vs open surgery were observed among patients with stage I (P = .97), stage II (P = .62), or stage III disease (P = .09).
A total of 173 recurrences were observed; the most common were peritoneal carcinomatosis (n = 73; 38 in laparoscopic group vs 35 in open surgery group), hematogenous metastases (n = 36; 19 vs 17), and locoregional recurrence (n = 23; 11 vs 12), with no difference between groups in types of recurrence.
The overall correlation between 3-year relapse-free survival and 5-year overall survival on an individual level among all patients was ρ = 0.447 (95% CI = 0.393–0.498). The correlation was greatest among patients with stage III disease (ρ = 0.720), followed by stage II (ρ = 0.469) and stage I disease (ρ = 0.242).
The late complication rate was significantly lower in the laparoscopic vs open surgery group (P = .01), with complications occurring in 32 (6.5%) of 492 patients vs 53 (11.0%) of 482 patients. The most common complication in both groups was intestinal obstruction (2.6% vs 5.0%). Chronic wound complications occurred in 0.6% vs 1.9% of patients.
The investigators concluded: “The 5-year outcomes of the KLASS-02 trial support the 3-year results, which is the noninferiority of laparoscopic surgery compared with open gastrectomy for locally [advanced gastric cancer]. The laparoscopic approach can be recommended in patients with locally [advanced gastric cancer] to achieve the benefit of low incidence of late complications.”
Sang-Uk Han, MD, PhD, Ajou University School of Medicine, Suwon, and Han-Kwang Yang, MD, PhD, Seoul National University College of Medicine, are the corresponding authors for the JAMA Surgery article.
Disclosure: This study was supported by the National R&D Program for Cancer Control and Ethicon Endo-Surgery, Johnson & Johnson Company. For full disclosures of the study authors, visit jamanetwork.com.
